I have two bowls with gravel and some hornwort, guppy grass and 3 marimo balls each. One has a Betta and one has a goldfish and I feed them every day. Both bowls have super low nitrates, like well under 5, the yellow in the test is slightly darker than the zero on the card.

I know my kit is good as it shows nitrates on my community tank. I am amazed that these bowls do so well with just some plants and marimo balls.

Anyone else seen the water quality stay so good in small bowls like this?